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Zn(1−x)CoxO nanoparticles with (x = 0.05, 0.10, 0.15 and 0.20) were prepared by combustion method. Here we report our findings on electrical properties carried out on these materials from room temperature to 500 °C. Thermopower investigations carried out on the materials resulted in Seebeck coefficient showing a transition from positive to negative values with ‘x’ dependent enhancements. The material that exhibits a p-type semiconductor character at room temperature translates into an n-type of semiconductor at higher temperatures beyond 90 °C marked by a first order transition. Electrical resistivity and the activation energy being interrelated are seen to decrease with rising temperature due to increase in charge carrier concentration. Dielectric constant (e) and dielectric loss (tan δ) investigated as a function of frequency showed nearly exponential decline in their values with increasing frequency for all the samples. However temperature dependent ‘e’ and ‘tan δ’ show a peaking behaviour at lower temperatures with increasing trend at higher temperature as a result of increase in dielectric polarization. The DMS materials being ferromagnetic at room temperature are good temperature dependent semiconductors with high dielectric constant.

Dielectric constant e′ and dielectric loss e″ were measured in the frequency range of 500 Hz–3 MHz from room temperature (RT) to 350 °C for CoWO4 and CoWO4/PbWO4 nanocomposites sintered at 600 °C. Dielectric constant was found to be higher for nanocomposite samples as compared to CoWO4 sample and was maximum for Pb/Co ratio optimal value of 0.028. Relaxor like anomaly and colossal dielectric constants were observed above RT due to Maxwell–Wagner effect without structural and phase transition of the materials. Relaxor like properties for these materials were confirmed by Vogel–Fulcher and modified Curie–Weiss laws. However the samples sintered at 1000 °C do not show relaxor like behaviour and exhibit low dielectric constant e′ at RT as compared to those sintered at 600 °C. P–E curve depicts the weak ferroelectric nature of the samples.

Cobalt-doped ZnO nanoparticles having chemical formula Zn(1-x)CoxO (x = 0.05, 0.10, 0.15, 0.20) were prepared by means of auto-combustion synthesis. Formation of monophasic wurtzite structure material was confirmed from XRD data. Inclusion of the Co2+ ions in the ZnO matrix produced several fascinating effects in the structural, physical and magnetic properties of the nanoparticles. The lattice constants ‘a’ and ‘c’ got inflated and the average crystallite size shriveled from 25 nm to 17 nm with the increase of Co concentration ‘x’ in the sample. The FT-IR spectra showed the characteristic absorption bands in the range of 400 cm−1 to 576 cm−1 due to formation of Zn O and Co O stretching bonds in the samples. Scanning Electron Microscope (SEM) images show agglomerates of particles that are spherical in nature. Energy dispersive spectroscopy (EDS) spectra of the samples giving molecular weight percentages of the elements Zn, Co and O in the samples are in agreement with the calculated percentages within the limit of permissible error. Hysteresis, FC, and ZFC measurements made on the samples, exhibit presence of ferromagnetic phase in the materials. Energy band gap estimates made with the help of UV spectroscopy indicated a decreasing trend of band gap with increasing ‘x’ in the sample. Photoluminescence studies carried out with excitation wavelength of 318 nm gave several emission peaks ranging from green to violet emissions. This observation confirms the presence of vacancies (defects) in the nanoparticle samples. Luminescence decay time recorded was in the range microseconds for all the samples.

Variations of Curie temperature and strength of magnetic phases with sintering temperature and Ni concentration is investigated in the present work. The AC susceptibility studies show a decrease in Curie temperature (TC) with an increase in Ni concentration in the samples. Comparison of Curie temperatures with the reported results reveals that samples in the present work show higher TC enabling high thermal stability. The Mossbauer spectra of nano- and sintered Ni-Zn ferrite samples were recorded at room temperature to monitor the local environment around Fe cations through Mossbauer hyperfine parameters as a function of composition and sintering temperatures. The increase in sharpness of the Mossbauer sextet with an increase in Ni concentration and sintering temperature corroborate improvement in homogeneity and ferrimagnetic ordering. The results of hyperfine parameters offer the possibility of having close view on configuring Curie temperature through monitoring hyperfine field by altering sintering temperature and/or Ni concentration. As the temperature dependence of magnetic and magnetoelastic properties is strongly influenced by the Curie temperature, the successful possible configuration of Curie temperature in the present work can be further investigated for desired sensor applications.

Single-phase nano-Ni–Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwave-assisted combustion method. Enhancement of saturation magnetization (Ms) was observed in comparison with previously reported results. Minor variation of (Ms) due to composition change can be explained on the basis of strengthening of A–B exchange interaction due to replacement of nonmagnetic Zn ions by Ni ions. Low coercivity (Hc) and retentivity (Mr) indicate low loss in the samples. SQUID analysis showed that the blocking temperature (TB) of the samples can be tailored in the present work.

Monophasic In(2-x)NdxO3 nanoparticle samples (x = 0, 0.10, 0.15, 0.20) with cubic bixbyite structure were prepared using auto-combustion method. A sizable increase in lattice constant ‘a’, and cell volume ‘V’ with a corresponding decrease in crystallite size ‘t’, ranging from 52 nm to 44 nm was observed with increasing Nd3+concentration in the material. Scanning Electron Micrographs exemplified the formation of spherically shaped particles in the materials. Energy dispersive X-ray spectroscopy established the presence of In, Nd and O in the samples. Fundamental absorption bands were identified in the range of 400 cm−1 to 700 cm−1whereas energy band gap decreased from 3.22 ± 0.09 eV to 3.14 ± 0.12 eV with increasing Nd3+ concentration in the sample. Induction of ferromagnetic character in the host matrix, which is an essential artifice of DMS materials, was a manifestation of magnetic hysteresis studies. FC and ZFC measurement further ascertained the evolution of the Nd3+ dependent ferromagnetic phase in the materials.

Rare earth (Nd 3+ ) doped Manganese-Zinc Ferrite nanoparticles with composition Mn 0.65 Zn 0.35 Fe 2-x Nd x O 4 (x = 0.04, 0.05 and 0.06) were prepared using combustion method of materials preparation. Formation of pure spinel phase was confirmed using X-ray diffraction (XRD) and Fourier transforms infra red spectroscopy (FTIR). The samples were exposed to various doses of γ-radiation (500Gy, 750Gy and 1000Gy) after recording the data on structural and electrical transport properties of as prepared samples, in order to study the effect of γ-radiation on these properties of the nanoparticles. Lattice constant ' a ' that showed a moderate increment with Nd 3+ doping was found to show a further increase after γ-radiation exposure with nearly a 30%–40% reduction in crystallite size. Transmission electron micrographs showed a decreasing trend of particle size that was nearly proportional to increasing dose of γ-radiation. The samples which showed enhancement in resistivity profile with increasing Nd 3+ concentration showed a reverse trend of decrease in the resistivity values with increasing γ radiation dose thus contributing to the conduction process. The dielectric constant of Nd 3+ doped samples showed a multifold increase in the dielectric constant with a further increase in its values for radiated samples, when referred to the values reported for undoped Mn-Zn nanoparticle ferrite materials.

CoWO4/PbWO4 nanocomposites were successfully synthesized at room temperature (RT) by co-precipitation route without using any templates or surfactants and sintered at 600 °C for good crystallization. The sintered samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy and Zeta potential measurements. UV–Visible diffuse reflectance spectroscopy, photoluminescence (PL) and PL lifetime were studied at RT. The results indicate that the composites have two-phase composition: CoWO4 and PbWO4. SEM micrograph and zeta potential measurements reveal particle agglomeration. The intrinsic PL peak emission at 467 nm of CoWO4 nano sample was enhanced upto four times by optimizing the atomic ratio of Pb/Co concentration. The interconnected interface of CoWO4/PbWO4 nanocomposites could have led to increase in number of recombination of electron hole pairs in CoWO4 and enhanced its intrinsic PL emission intensity. The mechanism of enhanced PL emission for the CoWO4/PbWO4 nanocomposites can be attributed to charge transfer between [WO4]2− and [WO6]6− complexes due to intra particle agglomeration leading to possible interface.

Ultrafine nanopowders of Mn 0.6 Zn 0.4 Fe 2-x Nd x O 4 ( x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd +3 doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd +3 doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd +3 concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd +3 doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd +3 doping. Magnetic parameters namely saturation magnetization (M S ) and net magnetic moment η B , estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd +3 doping. Mossbauer spectroscopy was employed to study the magnetic environment of Mossbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mossbauer spectra indicate the presence of Fe +3 ions at tetrahedral site (A-site) and octahedral site (B-site), respectively.

Nanoparticles of Mn x Zn(1−x)Fe2O4 with x = 0.5, 0.6, 0.7, 0.8 were prepared for the first time with metal oxides as raw material, using simple inexpensive combustion technique at low temperature. Formation of nanoparticle material was confirmed from X-ray diffraction (XRD) data and transmission electron microscopy (TEM) micrographs. Magnetic measurements, carried out with VSM, SQUID, and AC susceptibility equipment, show formation of samples with single-domain grains as well as samples with multidomain grains. A large shift in superparamagnetic blocking temperature, below room temperature with increasing magnetic field, was also observed.

Structural, AC conductivity, electrochemical and magnetic properties of CoWO4 and CoWO4/PbWO4 nanocomposites are reported in the present manuscript. Structural characterization and HRTEM images of the nanocomposites confirm interface formation. Room temperature (RT) DC conductivity (σdc) calculated from Jonscher power law, carrier concentration (N) and carrier mobility (μ) of the interfaced sample with maximum agglomeration (P2) are 6.7 times, 3 orders and 4 orders higher than that of CoWO4 sample respectively. Enhanced AC conductivity is also observed for P2 sample. These enhanced properties of P2 sample are due to the space charge layer (SCL) formation at the interface. Conduction models for all the samples are explained in detail. The specific capacitance (calculated from GCD curve) of the CoWO4 sample is 2.1 times larger than the CoWO4/PbWO4 nanocomposite for 1 A/g of current density. Paramagnetic behaviour at (RT) and antiferromagnetic nature below the transition temperature (TN) are observed for all the samples.

Nanoparticle magnetic materials are suitable for multiple modern high end medical applications like targeted drug delivery, gene therapy, hyperthermia and MR thermometry imaging. Majority of these applications are confined to use of Mn–Zn ferrite nanoparticles. These nanoparticles are normally left in the body after their requisite application. Preparing these nanoparticles is usually a much involved job. However with the development of the simple technique Mn x Zn 1− x Fe 2 O 4 nanoparticles could be prepared with much ease. The nanoparticles of Mn x Zn 1− x Fe 2 O 4 with ( x =1.0, 0.7, 0.5, 0.3, 0.0) were prepared and irradiated with gamma radiation of various intensities ranging between 500 R to 10,000 R, after appropriate structural and magnetic characterization. Irradiated samples were investigated for structural and magnetic properties, as well as for structural stability and cation distribution. The irradiated nanoparticles exhibited structural stability with varied cation distribution and magnetic properties, dependent on gamma radiation dose. Surprisingly samples also exhibited quenching of lattice parameter and particle size. The changes introduced in the cation distribution, lattice constant, particle size and magnetic properties were found to be irreversible with time lapse and were of permanent nature exhibiting good stability even after several months. Thus the useful properties of nanoparticles could be enhanced on modifying the cation distribution inside the nanoparticles by application of gamma radiation.

Nanoparticles of Mn0.2Zn0.8Fe2O4 were chemically synthesized by co-precipitating the metal ions in aqueous solutions in a suitable alkaline medium. The identified XRD peaks confirm single phase spinal formation. The nanoparticle size authentication is carried out from XRD data using Debye Scherrer equation. Thin film fabricated from this nanomaterial by pulse laser deposition technique on quartz substrate was characterized using XRD and Raman spectroscopic techniques. XRD results revealed the formation of high degree of texture in the film. AFM analysis confirms nanogranular morphology and preferred directional growth. A high deposition pressure and the use of a laser plume confined to a small area for transportation of the target species created certain level of porosity in the deposited thin film. Magnetic property measurement of this highly textured nanocrystalline Mn–Zn ferrite thin film revealed enhancement in properties, which are explained on the basis of texture and surface features originated from film growth mechanism.

Patterned nano crystalline ZnFe 2 O 4 thin film was fabricated on quartz substrate by pulse laser deposition. XRD and Raman spectroscopic techniques were employed for structural characterization of the film. Silencing of a small number of prominent ferrite XRD peaks in thin film signify mild textured film growth. The observed XRD peak position swing with respect to the target material in thin film indicates formation of lateral strain in opposite directions during film growth. The thin film XRD peak position shift with target material data as reference is explained by suggesting an appropriate film growth model. Designated ferrite Raman emission peaks originated from film surface authenticates the stoichiometric and structural stability of ferrite material. AFM images indicate specific pattern formation with nanogranular morphology. Magnetic property measurements of the thin film revealed enhanced properties which are explained on the basis of texture, lattice strain, and surface features that are originated from patterned thin film growth.

MnxZn1-xFe2O4 nanoparticles were chemically synthesized by co- precipitating metal ions in alkaline aqueous solutions. The XRD peaks match up to spinel ferrites without any multi phase indication and clear visibility of ferrite FT-IR absorption bands confirm single phase spinal formation. Particle size derived from XRD data is authenticated by TEM micrographs. Thin films fabricated from this material on quartz substrate by pulse laser deposition were characterised using XRD. The XRD data revealed formation of spinel structure with a reasonable degree of texture. AFM analysis confirms nano granular film morphology with dimensions comparable to that of target grain. Magnetic data obtained from textured nanocrystalline Mn-Zn ferrite thin film measurements made known enhanced coercivity. The observed enhanced coercivity is explained with due consideration of film texture and surface disorder that originated from Mn concentration specific initial adsorption prior to nucleation, resulting in directional film growth.

Nanopowders of Mn x Zn 1− x Fe 2 O 4 with x =0.4, 0.5 and 0.6 were synthesized using a combustion synthesis method. X-ray diffraction (XRD) patterns obtained on samples confirmed formation of monophasic cubic phase material. Lattice parameters and X-ray densities were obtained from rietvield refinement of the XRD patterns. All samples were radiated with gamma radiation with a dose of 200 Gy obtained from 60 Co source. Structural and physical parameters, such as lattice constant, X-ray density and particle size, determined for as prepared samples ( S A ) and gamma irradiated samples ( S R ), showed extraordinary variations in their values. Saturation magnetizations (M S ), remnant magnetization (M R ) and coercive field (H C ) for both sets of samples illustrated an enhancement in their values for S R samples. Investigations were carried out using Mossbauer spectroscopy to divulge structural and magnetic information of all samples. Room temperature Mossbauer spectra were fitted with five magnetic sextets and a symmetric paramagnetic doublet for the data obtained on samples except for x =0.4, S A sample. The presence of well defined doublets in the spectra of S A and S R samples is attributes of superparamagnetism, indicating the reduction in A–B superexchange interaction due to dilution of sub-lattice by Zn ions. Cation distribution at A site and B site, estimated from Mossbauer data exhibited amazing alterations which were highly stable. The variations in physical, structural and magnetic properties observed are attributed to change of Fe 2+ /Fe 3+ and Mn +2 /Mn +3 ratios in gamma-irradiated samples.

The powder of Ni 0.40Zn 0.60Fe 2 O 4 nanoparticles is synthesized using a microwave-assisted combustion method. X-ray diffraction and IR spectrum analysis show that the sample has a single-phase spinel structure. Debye–Scherrer formula reveals a crystallize size of 49 nm ±5 %, whereas transmission electron microscopy (TEM) results show particle sizes in the range of 10 to 60 nm. Superparamagnetic nature of the sample was confirmed from a close hysteresis loop. The Curie temperature (T C) was found to be 422 ∘C and 30 K as a blocking temperature.

A series of core-shell type nanoparticle samples of MnxZn1-xFe2O4were prepared by auto-combustion technique with x=0.3, 0.5, 0.7, 1.0. Subsequent to the structural and electrical property investigation the samples were irradiated with gamma radiation for different time intervals using60Co source. A significant decrease in lattice parameter and particle size was observed in gamma irradiated samples. Electrical resistivity of irradiated samples was found to decrease with the increase in γ-radiation dose. Frequency and temperature dependent dielectric constant and dissipation constant measurements carried out showed multifold enhancement of dielectric constant with pragmatic increase in dielectric loss, in γ-irradiated samples.

Bulk Ni0.55Zn0.45Fe2O4 samples were obtained by sintering their nanopowder at 1100 ∘C, 1200 ∘C, and 1300 ∘C. Improvement in crystallinity on sintering was identified from increase in intensity of the XRD peaks and grain development in SEM micrographs. Saturation magnetization increased from 81.7 emu/g to 85.3 emu/g as the sintering temperature increased from 1100 ∘C to 1300 ∘C. Initial permeability increases whereas the relative loss factor, resonance frequency, and DC resistivity decreases with increasing the sintering temperature. Curie temperatures obtained from low field AC normalized susceptibility and permeability measurements are in good agreement. The DC resistivity of the samples in the present case is two orders higher than the reported values of samples prepared using conventional ceramic method.

Nanoparticle Ni1−xZnx Fe2O4 (x=0.35,0.45) samples were prepared successfully via microwave assisted combustion method. Synthesis of nanosize materials at a low temperature using a domestic microwave oven is the unique feature of this method and is being tried for the first time to produce NiZn ferrites. Single-phase formation of the samples was confirmed from X-ray analysis and IR spectrum. XRD data reveals that lattice parameter increases with Zn content ‘x’. Particle sizes calculated from XRD analysis are in good agreement with TEM results. Extent of spin canting at octahedral B-site is deduced from Yafet–Kittel angles. Surface properties and reduced particle size affects the Curie temperature.

Nitrilotriacetate precursors have been used for synthesis of oxide materials. High permeability Mn – Zn ferrite with general formula Mn x Zn 1-x Fe 2 O 4 where x=0.3/0.35/0.4/0.45/0.5/0.55/0.6/0.65/0.7 were prepared using this novel method. Formation of cubic spinel structure was confirmed by XRD, which also provided information on formation of fine particle material. The magnetic properties of these materials were investigated after sintering the same at 950°C, 1150°C, 1250°C and 1350°C in nitrogen atmosphere and at 1050°C in air and were found to be interesting.

Ni0.60Zn0.40Fe2O4 ferrite was prepared via microwave assisted combustion method and sintered at three different temperatures (1100, 1200 &1300 °C). The lattice constant and bulk density increases whereas the porosity decreases (from 12% to 8% at 1100 to 1300 °C) with increasing sintering temperature. High saturation magnetization value (72.9 emu/g) is observed for the sample sintered at 1200 °C. Room temperature Mossbauer spectroscopy provided information on the magnetic phase and amount of Fe at A and B site in the lattice. Isomer shift (δ) values show that iron is in high spin Fe+3 states. Quadrupole splitting (Δ) values show the cubic symmetry at A-sites, possibility of local distortion at octahedral site and increase in hyperfine field with sintering temperature.

Core shell type nanoparticle MnxZn1−xFe2O4 systems with x=0.55, 0.65 & 0.75 were prepared using autocombustion method. The systems were characterized using tools like XRD and IR for structure confirmation. Magnetic parameter measurements like Saturation magnetization and coercivity were obtained from hysteresis loop which exhibited a symmetry shift due to core shell nature of the nanoparticles. Nanoparticles of particle size between 21.2nm to 25.7nm were found to show 20 percent shrinkage after being radiated by the γ-radiation. This is due to variation in the cation distribution which also affects the cell volume of the cubic cell. Lattice constant reduction observed is reflected in the magnetic properties of the samples. A considerable hike in the saturation magnetization of the samples was observed due to enrichment of magnetic alignment in the magnetic core of the particles. Samples under investigation were irradiated with gamma radiation from Co60 source for different time intervals.

Nanoparticle dilute magnetic semiconductors (DMS) are becoming increasingly important due to their possible applications in spintronics, an emerging field where the conduction process in the materials is a spin-based process. Nanoparticles of Mn-doped ZnO (DMS) material with general formula Zn[Formula: see text]MnxO ([Formula: see text]) were prepared by opting single stage combustion synthesis process. The samples characterized, exhibited formation of monophasic nanoparticles of the sample with average particle size ranging between 17 nm to 23 nm. The calculations of energy bandgap made from UV absorption spectra showed variation of the bandgap from 2.18 eV to 2.32 eV. The magnetic measurements (VSM) made on the samples confirmed formation of a single diamagnetic (Zn[Formula: see text]Mn[Formula: see text]) and two namely (Zn[Formula: see text]Mn[Formula: see text]) (Zn[Formula: see text]Mn[Formula: see text]) paramagnetic samples. It is interesting to see that all the three magnetic profiles exhibit hysteresis type behavior both in diamagnetic form and paramagnetic form. The resistivity of the samples was of the order of 10[Formula: see text] Ohm-cm ([Formula: see text]-cm) at lower temperatures. Temperature-dependent resistivity curves exhibited peaking behavior for all the three samples which is very interesting. Temperature-dependent thermo-power profiles give an indication of [Formula: see text]-type semiconductor behavior with significantly deep and broad minima around 100[Formula: see text] which becomes sharper for sample with higher Mn concentration.

Nanoparticles Ni0.55Zn0.45Fe2O4 was synthesized at low temperature using novel precursor method. The single spinel phase crystallization of sample was confirmed using XRD and IR spectra. Nanosize particles were confirmed using XRD and TEM images. Isomer shift in Mossbauer spectral studies are consistent with Fe ions in trivalent state. DC resistivity was of the order of 108 ohm cm that is two orders higher than those reported for NiZn ferrites prepared by conventional ceramic method. The high resistivity was attributed to nanosize particles, absence of Fe+2 ions and method of preparation.

Nanoparticles of Ni0.45Zn0.55Fe2O4 were chemically synthesized by novel precursor method at low temperature. Average particles size was found to be 37 nm. The Mossbauer spectroscopy studies were carried out on the sample for the investigation of magnetic and structural arrangement of Fe in the nano‐crystalline ferrite samples. The values of isomer shift are consistent with Fe ions in trivalent state. The low values of the quadrupole splitting identifies that the local symmetry of the magnetic phase of A—sites is close to cubic while that of B—site is close to trigonal. The broad collapsing sextet B1 can be correlated to the presence of relaxation effect in the sample.

Spinel ferrites are commercially important materials due to their excellent electrical and magnetic properties. Mixed metal spinel ferrites, essentially with low hysteresis loss and small particle sizes, have found new applications in areas like biosensors, drug delivery systems, and hyperthermia. The electrical conductivity, which gives credible information about conduction mechanism, is one of the important properties of ferrites. The order of magnitude of conductivity greatly influences the dielectric and magnetic behavior of the ferrites and depends on the preparative method. The present work deals with investigations into electrical, dielectric and thermo power parameters of CoxZn1-xFe2O4 ferrite nano particles synthesized by co-precipitation method. The effect of variation of the cobalt concentration in the sample on transport properties of nano ferrites has been analyzed.

This paper deals with optical absorption and photoluminescence properties of nanorange (22–65 nm) luminescent materials Co1−x Ce x WO4 (where x = 0.01, 0.015, 0.02, 0.025 and 0.03) sintered in air at various temperatures. These compounds were prepared by the solution-based co-precipitation method and characterized by x-ray powder diffraction and thermal analysis. Optimum conditions for high luminescence emission were obtained.

The amazing magnetic properties exhibited by nanoparticles Mn–Zn ferrites and their promising technological and medical applications have attracted much interest in recent years. Nanoparticle Mnx Zn(1–x)Fe2O4 spinel ferrites with x = 0.6/0.63/0.65/0.67/0.7 were synthesised by the nitrilotriacetate precursor method employing microwave combustion synthesis. Powder X–ray diffractometry (XRD) confirmed the formation of the ferrite phase in all samples. IR analysis was done to verify formation of spinel structure. Elemental analysis using EDS confirmed the nanoparticle composition. The crystallite size was calculated from peak widths using the Scherrer formula, yielding a size in the range of 10?25 nm. Transmission electron microscopy was also performed on the samples to testify formation of nanosized crystallites in the sample. Saturation magnetisation (Mr), retentivity (Ms) and coercivity (Hc) measurements were carried out on the samples using standard hysteresis loop tracer equipment. The saturation magnetisation values were found to be in the range of 58.6?63.2 emu/g with very low values for (Mr/Ms). Variation of specific magnetisation with temperature and Curie temperature measurements were carried out using pulse field AC susceptibility measuring equipment. These measurements indicated formation of single domain (SD) material with dependence of Curie temperature on Zn concentration. The density of the samples was found to be high.

Ferrite material nanoparticles comprised of manganese and zinc were chemically synthesized by the co-precipitation method. The designated ferrite X-ray diffraction peaks and characteristic ferrite absorption bands in Fourier transform infrared absorption spectra confirmed the formation of a spinel structure. Determination of the full width at half maximum values of the X-ray diffraction peaks and the corresponding calculations using the Scherrer formula suggested the generation of nano-grains. Micrographs obtained using a transmission electron microscope confirmed the nano-scale dimensions of the particles. Deviations in the characteristic resistivity and thermopower values in response to ambient sample temperature variations were experimentally observed and used for correlation-derived temperature-dependent transport behaviour analysis. Samples with a concentration x = 0.8 and 1.0 showed high thermopower values at reasonably low temperatures with moderate specific resistance.